Hydrocarbon conversion process

ABSTRACT

A process for producing gasoline blending stock which comprises (a) feeding an alcohol and a light hydrocarbon mixture containing at least tertiary olefins, linear olefins and isobutane to an etheration zone, (b) reacting the alcohol with the tertiary olefins in the etheration zone to obtain an ether and unreacted linear olefins and isobutane, (c) separating the ether from the linear olefins and isobutane, (d) feeding water and at least the linear olefins to a hydration zone, (e) reacting the water with the linear olefins in the hydration zone to obtain at least a secondary alcohol, (f) oxidizing the isobutane to obtain t-butyl alcohol, and (g) blending at least portions of the ether, secondary alcohol and t-butyl alcohol to produce a gasoline blending stock.

United States Patent Kozlowski et a1.

[ HYDROCARBON CONVERSION PROCESS [75] Inventors: Robert H. Kozlowski,Berkeley;

Robert P. Sieg, Piedmont; John W. Scott, Ross, all of Calif.

[73] Assignee: Chevron Research Company, San Francisco, Calif.

22 Filed: June 26,1970

21 App]. No.: 50,123

[52] US. Cl. 44/56, 44/77 [51] Int. Cl C101 1/18 [58] Field of Search44/56, 77; 260/614 A, 641

[56] References Cited UNITED STATES PATENTS 2,085,499 6/1937 James 44/562,118,881 5/1938 Francis 260/641 X 2,827,500 3/1958 Bloecher et al260/641 2,952,612 9/1960 Trainer 44/56 3,007,782 11/1961 Brown et al44/56 3,224,848 12/1965 Henderson 44/56 3,482,952 12/1969 Sieg et a].44/56 3,530,060 9/1970 Offenhauer 208/60 Nov. 19, 1974 PrimaryExaminer-Daniel E. Wyman Assistant Examiner-W. J. Shine Attorney, Agent,or Firm-G. F. Magdeburger; R. H. Davies; J. J. DeYoung [57] ABSTRACT Aprocess for producing gasoline blending stock which comprises (a)feeding an alcohol and a light hydrocarbon mixture containing at leasttertiary olefins, linear olefins and isobutane to an etheration zone,(b) reacting the alcohol with the tertiary olefins in the etherationzone to obtain an ether and unreacted linear olefins and isobutane, (c)separating the ether from the linear olefins and isobutane, (d) feedingwater and at least the linear olefins to a hydration zone, (e) reactingthe water with the linear olefiins in the hydration zone to obtain atleast a secondary alcohol, (f) oxidizing the isobutane to obtain t-butylalcohol, and (g) blending at least portions of the ether, secondaryalcohol and t-butyl alcohol to produce a gasoline blending stock.

6 Claims, 1 Drawing Figure 1 HYDROCARBON CONVERSION PROCESS BACKGROUNDOF THE INVENTION The present invention relates to a combination processto produce a gasoline blending stock. More particularly, the presentinvention relates to a process combination involving etheration,hydration, and partial oxidation to produce a gasoline blending stock.

Previously, high octane gasoline has generally been produced by blendinglead compounds as, for example, tetra methyl lead or tetra ethyl lead,with gasoline. However, it is presently believed that lead compounds ingasoline contribute to air pollution or that lead compounds in thegasoline increase the difficulty of controlling emissions from internalcombustion engines.

Components such as ethers have been suggested as blending components forgasoline, but few overall processes have been suggested for producingetherated gasolines. US. Pat. No. 3,482,952 suggests a process forproducing etherated gasoline.

According to the process disclosed in U.S. Pat. No. 3,482,952, etheratedgasoline is produced by reacting C -C tertiary olefins obtained from acracking reactor with a lower alcohol to obtain ethers. These ethers arethen blended with at least one other hydrocarbon stream.

SUMMARY OF THE INVENTION According to the present invention, a processis provided for producing a gasoline blending stock which processcomprises (a) feeding an alcohol and a light hydrocarbon mixturecontaining at least tertiary olefins, linear olefins and isobutane to anetheration zone, (b) reacting the alcohol with the tertiary olefins inthe etheration zone to obtain an ether and unreacted linear olefins andisobutane, (c) separating the ether from the linear olefins andisobutane, (d) feeding water and at least a portion of the linearolefins to a hydration zone, (e) reacting the water with the linearolefins in the hydration zone to obtain a secondary alcohol, (f)oxidizing the isobutane to obtain at least t-butyl alcohol, and (g)blending at least portions of the ether, secondary alcohol and t-butylalcohol to produce a gasoline blending stock.

According to a preferred embodiment of the present invention, both theisobutane and linear olefins are fed to the hydration zone and unreactedisobutane is withdrawn from the hydration zone and is oxidized to obtaint-butyl alcohol.

In the present specification, the term tertiary olefin is used to meanthose olefins containing a carbon atom bonded to three other carbonatoms with one of the bonds being a double bond. The term linear olefinis used in the present specification to mean olefins other than tertiaryolefins and thus to include branched chain olefins wherein the branchingdoes not result in a tertiary olefin. Thus, the term linear olefinincludes propylene, butene-2, etc.

According to a particularly preferred embodiment of the presentinvention, the light hydrocarbon mixture which is fed to the etherationzone contains normal butane in addition to tertiary olefins, linearolefins and isobutane, and, after passing through the etheration andhydration zones, the normal butane is isomerized to obtain isobutane andat least a portion of the isobutane obtained by isomerization isoxidized to t-butyl alcohol. I

The alcohol fed to the etheration zone for reaction with the tertiaryolefins in accordance with the process of the present invention can beone or a mixture of alcohols ranging from C alcohols up to high alcoholssuch as C alcohols. However, it is preferred that the alcohol or alcoholmixture fed to the etheration zone be a lower alcohol such as methanolup to about the amyl alcohols. It is particularly preferred in theprocess of the present invention to feed methanol to the etherationzone. Methanol is a relatively inexpensive alcohol and we have alsodetermined that methanol can be pro duced in an overall refinerycombination process including the basic steps of the present invention.As is discussed in more detail hereinbelow, one of the importantadvantages of the present invention is its versatility and ability tocombine with other refinery process steps. The methanol feed to theprocess of the present invention can be obtained from a combinationhydrogen-methanol production plant with the hydrogen produced in thecombined hydrogen-methanol plant being used in a hydrocracking plantwhich hydrocracking plant in turn supplies at least a portion of theisobutane for reaction in the isobutane oxidation step according to thepresent invention. Combined hydrogen and methanol production isdiscussed in more detail in the commonly assigned applications entitledGasoline Production, application Ser. No. 46,264, Production ofGasoline," Ser. No. 46,230, and Manufacture of Gasoline, Ser. No.46,217, all of which were filed on June 15, 1970. The threeaforementioned patent applications are incorporated by reference intothe present patent application.

The light hydrocarbon mixture fed to etheration zone 3 preferably boilsbetween about propylene and 400F.

More preferably, the light hydrocarbon stream comprises hydrocarbonswithin the range of about C to C The hydrocarbon mixture fed to theetheration zone can be produced or obtained in a variety of ways.Different streams produced in a refinery, for example, can be combinedto obtain the light hydrocarbon mixture for feeding to etheration zone3. It is particularly preferred in the process of the present inventionto feed an olefin-rich C -C stream from a hydrocarbon cracking processto etheration zone 3. The C -C stream from the cracking process can be arelatively pure olefin stream containing only a few tenths percent or soparaffins such as isobutane, or the C -C stream may contain substantialamounts of parafiins such as 5 50 weight percent paraffins. One of theimportant advantages of the present invention is that both theetheration and hydration steps in the present invention operate asserial separation steps, i.e., in the etheration zone, tertiary olefinsare converted to ethers which ethers are then easily separated from theremaining olefins and paraffins compared to the difficulty in separatingtertiary olefins directly from the linear olefins. And in hydration zone6, the linear olefins are reacted with water to form alcohols whichalcohols are usually relatively easily separated from the remainingparaffins compared to the difficulty of separating the C -C paraffinsfrom the C -C linear olefins.

The preferred olefin-rich C.,-C stream for feeding to etheration zone 3in the process of the present invention can be obtained, for example,from a light hydrocarbon cracking process or a cracking process appliedto a relatively heavy hydrocarbon such as gas oil. The cracking processcan be thermal or catalytic. Suitable cracking processes operated atcracking temperatures between about 900 and 1200F. are described in U.S.Pat. No. 3,482,952 at column 3, line 22 to line 46, which disclosure isincorporated by reference into the present specification. It ispreferred to obtain the olefin-rich light hydrocarbon mixture forfeeding to the etheration zone in the present invention from a catalyticcracking process such as a fluid catalytic cracking process applied torelatively heavy hydrocarbons such as gas oils.

Although C C olefin-rich streams are advantageous feedstocks for theetheration reaction in the process of the present invention, streamscontaining mostly C olefins are the most preferred feedstock for theetheration reaction in the process of the present invention. Preferably,the C olefin-rich feed stream is obtained by distilling a C rich cutfrom the effluent from a hydrocarbon cracking process such as a fluidcatalytic cracking process. The C olefin-rich cut is a particularlypreferred feedstock for the etheration reaction in the process of thepresent invention because the isobutene in the C, out has a relativelyhigh reaction rate with alcohols such as methanol to form etherscompared to the reaction rates of higher tertiary olefins with alcoholsto form ethers. Furthermore, we have determined that the methyl t-butylether formed in reacting isobutene with methanol has relatively highoctane blending numbers when blended with gasoline boiling rangehydrocarbons. Still further, the olefin-rich C. stream provides arelatively high concentration of olefins compared to wider cuts such asC C olefin-rich hydrocarbon fractions and this higher concentration ofolefins contributes to the efficiency of the process of the presentinvention. In the process of the present invention, unreacted linearolefins and paraffins are removed from the etheration zone and passed atleast in part to the hydration reaction step of the present invention.The preferred olefin-rich C, fraction provides a relatively highconcentration of linear butenes for hydration to produce at leastsecondary butyl alcohol in the hydration step of the present invention.The secondary butyl alcohol has a relatively high blending octane numbercompared to higher secondary alcohols. Unreacted isobutane (iC withdrawnfrom the hydration reaction step in the process of the present inventionis oxidized in the partial oxidation step of the present invention toform t-butyl alcohol which has a relatively high blending octane numberwhen blended with gasoline boiling range hydrocarbons.

As indicated above, preferably at least a portion of the paraffinic Cfeed for the process of the present invention is obtained from ahydrocracking process. Hydrocracking using Group VIB and/or Group VIIIcomponents on acidic supports such as silica-alumina producessubstantial quantities of isobutane. The isobutane is advantageouslyoxidized in the partial oxidation step of the present invention to formthe relatively high blending octane number component t-butyl alcohol.

The hydrocrackingor other hydroconversion step such as hydrotreating orhydrofining can advantageously be combined with fluid catalytic crackingto produce at least a portion of the feedstock for the catalyticcracking process. According to a preferred overall embodiment of thepresent invention, hydroconversion is used to provide at least a portionof the isobutane which is converted to t-butyl alcohol, at least aportion of the effluent from the hydroconversion step is fed to acatalytic cracking process which provides at least a portion of the Colefins fed to the etheration step of the present invention andpreferably, at least a portion of the ethers and alcohols produced inthe etheration, hydration and/or partial oxidation steps of the presentinvention are blended with at least a portion of the gasoline boilingrange hydrocarbons produced in the hydroconversion and/or catalyticcracking steps.

According to one preferred alternate overall process embodiment inaccordance with the present invention, a process is provided forproducing a gasoline blending stock which comprises (a) feeding analcohol and a C, C stream, containing at least tertiary olefins, linearolefins, isobutane, n-butane and isopentane, to an etheration zone, (b)reacting the alcohol with the tertiary olefins in the etheration zone toobtain an ether, (0) separating the ether from unreacted linear olefinsand paraffins, (d) feeding water and the unreacted linear olefins andparaffins to a hydration zone, (e) reacting the water with the unreactedlinear olefins in the hydration zone and withdrawing at least asecondary alcohol and unreacted paraffins from the hydration zone, (f)separating the secondary alcohol from the unreacted paraffins, (g)separating the unreacted paraffins into at least isobutane andisopentane, (h) oxidizing the isobutane to obtain t-butyl alcohol, (i)blending at least a portion of the ether, secondary alcohol and t-butylalcohol to produce a gasoline blending stock.

The gasoline blending stock produced in accordance with the presentinvention can be blended with various gasoline boiling rangehydrocarbons to obtain an unleaded relatively high octane gasoline.

BRIEF DESCRIPTION OF THE DRAWING The drawing is a schematic process flowdiagram illustrating a preferred embodiment of the process of thepresent invention.

DETAILED DESCRIPTION OF THE DRAWING Referring now more particularly tothe drawing, a hydrocarbon mixture containing tertiary olefins, linearolefins, and isobutane is fed via line 1 to etheration zone 3. Inetheration zone 3, the tertiary olefins are reacted with alcohol fed vialine 2 to obtain an ether which is withdrawn from the etheration zonevia line 4. It is, of course, to be understood that distillationfacilities will be operated in conjunction with the etheration reactorin etheration zone 3.

To catalyze the ether synthesis reaction in zone 3, solid acidic orhomogeneous acidic catalysts can be used. Preferred temperatures for usein the ether synthesis reactor are between and 225F. and preferredpressures are between 10 and 600 psig. Preferred cata lysts for use inthe ether synthesis reactor are relatively high molecular weight,water-insoluble, carbonaceous materials containing at least one SO Hgroup as the functional group. These catalysts are exemplified by thesulfonated coals (Zeo-Karb H, Nalcite X, and Nalcite AX) produced by thetreatment of bituminous coals with sulfuric acid and commerciallymarketed as zeolitic water softeners or base exchangers. These materialsare usually available in a neutralized form and, in this case, must beactivated to the hydrogen form by treatment with a mineral acid, such ashydrochloric acid, and water washed to remove sodium and chloride ionsprior to use. Also suitable are the sulfonated resin type catalystswhich include the reaction products of phenolformaldehyde resins withsulfuric acid (Amberlite lR-l, amherlite IR-l00, and Nalcite MX). Alsouseful are the sulfonated resinous polymers of coumarone indene withcyclopentadiene, sulfonated polymers of coumarone indene with furfural,sulfonated polymers of coumarone indene with cyclopentadiene andfurfural, and sulfonated polymers of cyclopentadiene with furfural. Themost preferred cationic exchange resins are strongly acidic exchangeresins consisting essentially of sulfonated polystyrene resin, forinstance, a divinylbenzene cross-linked polystyrene matrix having about0.5 to 20 percent, preferably about 4 to 16 percent, of copolymerizeddivinylbenzene therein to which are attached ionizeable or functionalnuclear sulfonic acid groups. These resins are manufactured and soldcommercially under various trade names; e.g., Dowex 50, Nalcite HCR, andAmberlyst 15. As commercially obtained, they have solvent contents ofabout 50 percent and can be used in the instant process in this form orcan be dried and then used.

Particularly preferred as a catalyst for use in the ether synthesis zoneis Amberlyst which is a divinylbenzene cross-linked polystyrene matrix,having between 0.5 percent of copolymerized divinylbenzene by weight ofthe resin catalyst to which is attached sulfonate groups, and having amacroreticular structure. More specifically, Amberlyst 15 has thefollowing properties:

Property H Amberlyst 15 16 mesh U.S. Standard Screens 2.4 l6 20 meshU.S. Standard Screens 24.2 -20 30 mesh U.S. Standard Screens 47.9 -30 40mesh U.S. Standard Screens 18.8 40 50 mesh U.S. Standard Screens 5.7Through 50 mesh, percent 1.0 max. Whole bead content. 100 Bulk density,g/l as supplied 850 lbs/cu. ft. 54 True density. g/ml as supplied 1.4Mositure. by weight less than 1% Solids. 55:69 M 7 Percentage swellingfrom dry state to solvent-saturated state hexane l2 toluene l5 ethylenedichloride l7 ethyl acetate 35 ethyl alcohol (95%) 66 water 66 Hydrogenion concentration meq./g. dry 4.9 meq./ml. packed column 2.4 SurfaceArea, m 40 5O Porosity, ml. porefml. bead .30 .35 Average Pore Diameter,A 200 600 As can be seen from the properties given above, Amberlyst 15is generally obtained with a hydrogen ion concentration (SO Hconcentration) of about 4.9 meq. per gram of catalyst.

The term macroreticular is used herein to connote a resin catalyst porestructure having a high degree of true porosity, that is, pores whichare rigid and fixed within the resin beads. The high porosity gives riseto a large surface area which is conducive to high catalytic activity.The macroreticular structure in Amberlyst 15 alysts. Preferredtemperatures for the hydration of olefins in hydration zone 6 arebetween about and 325F. and preferred pressures are between about 50 and500 psig. Preferred catalysts for use in the hydration zone includethose mentioned above for use in the ether synthesis zone, but somewhatreduced acidity is preferred for the hydration catalysts compared to theether synthesis catalyst. Thus, Amberlyst 15 with the acidity adjustedto between about 0.5 and 2.5 meq. l-l+/g. of catalyst is a particularlypreferred catalyst for use in the hydration zone.

Distillation facilities are an included part of hydration zone 6. In thedistillation facilities, unreacted paraffins are separated from thesecondary alcohol. The unreacted isobutane and other paraffins such asnormal butane and isopentane are fed to distillation column 11.

According to a preferred embodiment of the present invention, additionalbutanes are also fed to distillation column 11 as indicated by line 10in the drawing. Isopentane and, in general, hydrocarbons with lessvolatility than normal butane, are fractionated downward in distillationcolumn 11. An isopentane-rich stream is withdrawn from the bottom of thedistillation column via line 12. This isopentanerich stream isadvantageously used as a gasoline blending component as isopentaneitself has a relatively high octane number.

A side-stream rich in normal butane is preferably withdrawn from theupper part of the distillation column as a liquid draw from a sump trayor the like at some position intermediate between the top of the columnand the feed point to the column, or a normal butane-rich stream can bewithdrawn from the lower part of the distillation column as a vapor sidestream withdraw. in accordance with a preferred embodiment of thepresent invention, the normal butane is isomerized in C isomerizationzone 14 to produce additional butane. The isomerization of normal butanein zone 14 can be carried out using, for example, a platinum on silicaalumina or platinum on chlorided alumina catalyst. Preferred operatingtemperatures for the normal butane isomerization are between about 200and 750F. and preferred pressures are between about and 1000 psig. In atypical normal butane isomerization process, a deisobutanizer isoperated in conjunction with the isomerization reactor. However, in theprocess of the present invention, it is preferred to use distillationcolumn 11 in conjunction with C isomerization zone 14 rather than to usea separate deisobutanizer column to further purify the normal butanefeed passed via line 13 to zone 14. Zone 14 will, however, contain someseparating and heating equipment oprating in conjunction with the normalbutane isomerization reactor. A typical normal butane isomerizationprocess is described in the Oil and Gas Journal, Volume 56, No. 13, Mar.31, 1958, at pages 73 76.

The normal butane feed to zone 14 is largely converted to isobutanewhich is withdrawn from zone 14 via line 15 and fed to distillationcolumn 11 via line 16 and 9. Isobutane is distilled overhead indistillation column 11 and is withdrawn via line 17. The isobutanerichstream withdrawn via line 17 is fed to partial oxidation zone 18 whereinthe isobutane is oxidized preferably with molecular oxygen or oxygenpresent in ordinary air introduced to zone 18 via line 19. In thosecases where air is used to supply the oxidizing gas for zone 18, anitrogen-rich stream is removed from zone 18 via line 20. A number ofmethods can be employed to effect the oxidation of the isobutanefeedstock to zone 18 toform tertiary butanol.

Preferably, the oxidation is carried out in the presence of a catalystcontaining cobalt, copper or nickel or combinations thereof. Accordingto recent laboratory work, it has been found that high conversions ofliquid isobutane to tertiary butanol can be obtained while usingreaction conditions including a tempera- EXAMPLE Table 1 belowsummarizes the feed and products obtained according to an exampleembodiment of the present invention.

Fccd

Mixcd Butancs Water Methanol C, Olcfins Air ture between 150 and 500F.and a pressure between 200 and 1000 psig by contacting the liquidisobutane with a catalyst comprising at least one of the elementscopper, nickel, cobalt, iron, and manganese. Preferred operatingtemperatures are between 150 and 400F. and preferred pressures arebetween 100 and 500 psig for the oxidation of isobutane to obtain highyields of tertiary butanol. Air or pure oxygen can be used as theoxidant.

In particular, in laboratory experiments at 200F. and 600 psig, aconversion of 91.7 percent of feed liquid isobutane to tertiary butanolwas obtained. The product analysis was as follows:

lsobutane 7. l 8 weight percent Water 9.33 weight percent t-Butanol 81.7weight percent t-Butyl Hydroperoxide 0.67 weight percent Di-t-ButylPeroxide 0.75 weight percent to convert it by reaction with an olefin toform addi-- tional t-butanol. For example, the t-butyl hydroperoxide canbe reacted with propylene to form t-butanol and propylene oxide.

The tertiary butanol produced in zone 18 is withdrawn via line 21 andpreferably is blended with ethers and alcohols withdrawn from zones 3and 6, respectively, to produce a relatively high octane gasolineblending component in line 22. Although any one or more of therespective ether, secondary alcohol and tertiary butanol streamsproduced in the present invention can advantageously be used as gasolineblending in Table I is fed to etheration zone 3 wherein the methanol isreacted with tertiary olefins present in an olefinrich stream fed toetheration zone 3 via line 1. The olefin-rich stream contains a minoramount of normal and isobutane and about 67 weight percent of the Colefins is isobutene. Thus, the primary product produced in zone 3 istertiary butyl methyl ether.

Unreacted linear olefins and paraffins are withdrawn from zone 3 vialine 5 and fed to hydration zone 6. In hydration zone 6, the linearolefins are reacted with about 500 barrels per day of water introducedvia line 7 to produce about 2,500 barrels per day of secondary butylalcohol which is withdrawn from zone 6 via line 8. The small amount ofbutanes present in the feed to etheration zone 3 remain unreacted afteretheration zone 3 and hydration zone 6. These butanes are fed todistillation column 11 along with additional mixed butanes fed via lines10 and 16 to column 11. The addi tional mixed butane stream introducedvia line 10 is withdrawn from various refinery processes includinghydrocracking. Distillation column 11 is operated in conjunction with Cisomerization zone 14 to produce an isobutane-rich stream which iswithdrawn via line 17 from column 11 and fed to partial oxidation zone18.

Only a relatively small amount of hydrocarbons and oxygenated componentsless volatile than normal butane are withdrawn via line 12 from thebottom of column 11.

The isobutane withdrawn from the top of column Ill is oxidized in zone18 to produce approximately 1 1,000 barrels per day of tertiary butylalcohol which is withdrawn via line 21. The combined tertiary butylmethyl ether, secondary butyl alcohol and tertiary butyl alcohol isabout 19,300 barrels per day. The combined gasoline blending stock ofabout 19,300 barrels per day has a boiling range of about 130 to 210F.and a research clear blending octane number of about 110 115 in octanegasoline.

The process of the present invention is particularly advantageous in itsflexibility and ability to combine with basic refinery processing stepssuch as catalytic cracking, hydrocracking and alkylation.

For example, the basic process of the present invention can be combinedwith alkylation as follows: A mixed hydrocarbon stream containing, forexample, mostly C hydrocarbons such as isobutane, normal butane,isobutene and normal butene is fed to etheration zone 3 via line 1. Theisobutene is reacted with metha nol introduced to zone 3 via line 2 toproduce tertiary butyl methyl ether. Also, a portion of the isobutene isreacted in etheration zone 3 with isopropyl alcohol to produce tertiarybutyl isopropyl ether which is a particularly good high octane gasolineblending component. The isopropyl alcohol can be produced in hydrationzone 6 from propylene introduced as a separate stream to hydration zone6. However, according to a preferred embodiment of the presentinvention, propylene contained in the mixed hydrocarbon feed toetheration zone 3 is used as the reactant to form isopropyl alcohol inhydration zone 6. Because the propylene does not contain a tertiarycarbon atom, it does not react to form an ether to any appreciableextent in etheration zone 3 and thus, etheration zone 3 serves toincrease the linear olefin (including propylene) content of the mixedhydrocarbon stream originally fed to the etheration zone.

Thus, unreacted linear olefins in the effluent from the etheration zoneare passed to hydration zone 6 wherein they are reacted with water toform secondary butyl alcohol, including isopropyl alcohol in thoseinstances when propylene is present in the mixed hydrocarbon feed to theetheration zone.

Preferably, a portion of the linear olefins in the effluent from theetheration zone are fed to an alkylation process such as a sulfuric acidor HF alkylation process to form a high octane gasoline boiling rangealkylate. The isobutane fed to the alkylation step can be obtaineddirectly as an outside isobutane stream, but preferably the isobutane isobtained in part from unreacted isobutane present in the effluent fromthe etheration zone and in part by nC, isomerization to increase the iCcontent of a mixed butane stream.

A portion of the isobutane withdrawn from distillation column lll vialine 17 is fed to partial oxidation zone 18 for production of tertiarybutyl alcohol. Particularly in those instances when there is a shortageof isobutene feed for etheration zone 3, it is advantageous in theprocess of the present invention to dehydrate at least a portion of thetertiary butyl alcohol to form isobutene which is fed to etheration zone3.

Thus, the oxygenated components which are produced in this embodiment ofthe present invention include tertiary butyl methyl ether, tertiarybutyl isopropyl ether, isopropyl alcohol, secondary butyl alcohol, andtertiary butyl alcohol. One or more of these relatively high octanegasoline blending components can be blended with the alkylate producedin accordance with this preferred embodiment of the present invention toobtain a high octane unleaded gasoline.

Although various embodiments of the invention have been described, it isto be understood that they are meant to be illustrative only and notlimiting. Certain features may be changed without departing from thespirit or scope of the invention. It is apparent that the presentinvention has broad application to the production of gasoline blendingstocks in a combination process involving etheration, hydration, andpartial oxidation. Accordingly, the invention is :not to be construed aslimited to the specific embodiments or examples discussed but only asdefined in the appended claims.

What is claim is:

l. A process for producing a gasoline blending stock which comprises:

a. feeding an alcohol and alight hydrocarbon mixture containing at leasttertiary olefins, linear olefins and isobutane to an etheration zone,

b. reacting the alcohol with the tertiary olefins in the etheration zoneto obtain an ether and unreacted linear olefins and isobutane,

c. separating the ether from the linear olefins and isobutane,

d. feeding water and at least a portion of the linear olefins to ahydration zone,

e. reacting the water with the linear olefins in the hy dration zone toobtain a product alcohol,

f. oxidizing the isobutane to obtain t-butyl alcohol,

and

g. blending at least portions of the ether, product alcohol and t-butylalcohol to produce a gasoline blending stock.

2. A process in accordance with claim 11 wherein both the isobutane andlinear olefins are fed to the hydration zone and unreacted isobutane iswithdrawn from the hydration zone and is oxidized to obtain t-butylalcohol.

3. A process in accordance with claim 1 wherein the light hydrocarbonmixture also contains n-butane and the n-butane is isomerized to obtainisobutane and at least a portion of the isobutane obtained byisomerization is oxidized to t-butyl alcohol.

4. A process in accordance with claim 1 wherein the light hydrocarbonmixture comprises C C hydrocarbons obtained from a hydrocarbon crackingprocess.

5. A process in accordance with claim 4 wherein the C -C hydrocarbonsare obtained from fluid catalytic cracking.

6. A process for producing a gasoline blending stock which comprises:

a. feeding an alcohol and a C -C cracking effluent stream, containing atleast tertiary olefins, linear olefins, isobutane, n-butane andisopentane, to an etheration zone,

b. reacting the alcohol with the tertiary olefins in the etheration zoneto obtain an ether,

c. separating the ether from unreacted linear olefins and paraff'ms,

d. feeding water and the unreacted linear olefins and paraffins to ahydration zone,

e. reacting the water with the unreacted linear olefins in the hydrationzone and withdrawing a product alcohol and unreacted paraffins from thehydration zone,

f. separating the product alcohol from the unreacted paraffins,

g. separating the unreacted paraffins into at least isobutane andisopentane,

h. oxidizing the isobutane to obtain t-butyl alcohol,

i. blending at least a portion of the ether, product alcohol and t-butylalcohol to produce a gasoline blending stock.

1. A PROCESS FOR PRODUCING A GASOLINE BLENDING STOCK WHICH COMPRISES: A.FEEDING AN ALCOHOL AND A LIGHT HYDROCARBON MIXTURE CONTAINING AT LEASTTERTIARY OLEFINS, LINEAR OLEFINS AND INSOBUTANE TO AN ETHERATION ZONE,B. REACTING THE ALCOHOL WITH THE TERTIARY OLEFINS IN THE ETHERATION ZONETO OBTAIN AN ETHER AND UNREACTED LINEAR OLEFINS AND ISOBUTANE, C.SEPARATING THE ETHER FROM THE LINEAR OLEFINS IN THE ETHERAD. FEEDINGWATER AND AT LEAST A PORTION OF THE LINEAR OLEFINS TO A HYDRATION ZONE,E. REACTING THE WATER WITH THE LINEAR OLEFINS IN THE HYDRATION ZONE TOOBTAIN A PRODUCT ALCOHOL. F. OXIDIZING THE ISOBUTANE TO OBTAIN T-BUTYLALCOHOL, AND G. BLENDING AT LEAST PORTIONS OF THE ETHER, PRODUCT ALCOHOLAND T-BUTYL ALCOHOL TO PRODUCE A GASOLINE BLENDING STOCK.
 2. A processin accordance with claim 1 wherein both the isobutane and linear olefinsare fed to the hydration zone and unreacted isobutane is withdrawn fromthe hydration zone and is oxidized to obtain t-butyl alcohol.
 3. Aprocess in accordance with claim 1 wherein the light hydrocarbon mixturealso contains n-butane and the n-butane is isomerized to obtainisobutane and at least a portion of the isobutane obtained byisomerization is oxidized to t-butyl alcohol.
 4. A process in accordancewith claim 1 wherein the light hydrocarbon mixture comprises C4-C5hydrocarbons obtained from a hydrocarbon cracking process.
 5. A processin accordance with claim 4 wherein the C4-C5 hydrocarbons are obtainedfrom fluid catalytic cracking.
 6. A process for producing a gasolineblending stock which comprises: a. feeding an alcohol and a C4-C5cracking effluent stream, containing at least tertiary olefins, linearolefins, isobutane, n-butane and isopentane, to an etheration zone, b.reacting the alcohol with the tertiary olefins in the etheration zone toobtain an ether, c. separating the ether from unreacted linear olefinsand paraffins, d. feeding water and the unreacted linear olefins andparaffins to a hydration zone, e. reacting the water with the unreactedlinear olefins in the hydration zone and withdrawing a product alcoholand unreacted paraffins from the hydration zone, f. separating theproduct alcohol from the unreacted paraffins, g. separating theunreacted paraffins into at least isobutane and isopentane, h. oxidizingthe isobutane to obtain t-butyl alcohol, i. blending at least a portionof the ether, product alcohol and t-butyl alcohol to produce a gasolineblending stock.